You Can Use The Code in WordPress CMS Custom Post loop

WordPress Custom Post Count Post Number and Add Class Odd Even Post and add class First Post

//Here is the code
<?php if ( $posts->have_posts() ) : //IF  POST AVAILABLE
						
	$count 	= 1;
	$Number = 1;

	while( $posts->have_posts() ) : $posts->the_post(); //WP CUSTOM QUERY

		// GET POST SUPPORT DATA
		$thumbnails = wp_get_attachment_image_src( get_post_thumbnail_id( get_the_ID() ), 'full');
		$content 	= wp_trim_words( get_the_content(), '250', '....' );

		// WORDPRESS POST COUNT ODD ADD EVEN POST ADD DIFFERENT CLASS
		if($Number % 2){
			$active = 'fadeInLeft';
		}else{
			$active = 'fadeInRight';
		}

		//WORDPRESS FIRST POST ADD CLASS
		if( $count == 1){
	        $activeblock = 'active-block';
	        $active = 'active';
	        $current = 'current';

	    }else{
	        $activeblock = ' ';
	        $active = ' ';
	        $current = ' ';
	    }	
	?>

	<div class="timeline-content wow <?php echo $Number; ?> <?php echo $active; ?>"></div>
						
	<?php $Number++; $count++;  endwhile;  wp_reset_postdata(); ?>

	<?php else : //ECHO POST NOT FOUND ?>
	    <?php esc_html_e( 'Sorry, No Post matched your criteria'); ?>
<?php  endif; ?>